The demand for portable applications such as laptop PCs, cell phones, and digital cameras is ever-increasing. These applications keep getting smaller and more advanced with tougher price competition every day. No application component can escape these toughening requirements, and the vital application power source, the battery, is certainly no exception. Battery capacity development is lagging behind the increasing demands from the application and control of the chemical reaction inside the battery is subject to severe safety requirements, making it difficult to push the limits of the chemical technology. To make life even more difficult for battery vendors, the battery is expected to shrink in size and price along with the rest of the application.
Advanced battery packs, or smart batteries, contain a large amount of electronic components. This includes fail-safe circuitry to ensure that the battery cell is not damaged or dangerous to the user; monitoring capabilities and logic to interpret battery conditions and estimate charge left depending on battery load; and communication with the host application. Current smart battery applications are implemented using at least two integrated circuits: a microcontroller for battery management and an analog front-end to ensure battery protection and measurements. In addition, some require a third chip, an EEPROM containing data specific to the battery chemistry, necessary for charge left estimation and other monitoring parameters. These solutions are costly and take up board space.
In addition, rechargeable battery cells typically have a low current capability. For applications where high instant energy is needed, this problem is overcome by using many cells in series. This results in a higher voltage allowing a higher energy with a lower current. The higher voltage is a problem for standard semiconductors as these typically can handle voltages between 2-5 volts. Smart battery vendors solve the high voltage input/output problem by using separate driver circuits. This adds to the cost, weight, and complexity of the system.
Accordingly, what is needed is a system and method for overcoming the above-identified issues. The present invention addresses such a need.